Detection Of Occult Metastasis In Lymph Nodes And Peripheral Blood From Colorect Cancer Patients: A Multi-marker Reverse Transcriptase-Polymerase Chain Reaction

Objective: we detected the expression of CEA CK20 MMP-7 with RT-PCR in lymph nodes and peripheral blood with colorectal cancer patients to test the sensitivity of occult metastasis in lymph nodes and peripheral blood with colorectal cancer patients.Methods:Forty two patients with colorectal cancer and ten benign bowel diseases undergoing colonic resection were enrolled,42 peripheral blood and 260 lymph nodes were gathered in cancer patients and 25 lymph nodes were gathered with benign bowel disease.RT-PCR was used to detect expression of the three epithelial markers CEA,CK20,MMP-7,in fresh colorectal lymph node tissue and peripheral blood.Results: of 45 histologically positive nodes,44 lymph nodes for CEA ,42 for CK20 and 43 for MMP-7 are positive respectly by RT-PCR; Of 215 histologiclly negative nodes,85 were positive for at least one of the three markers by RT-PCR,57 lymph nodes for CEA,51 lymph nodes for CK20,48 lymph nodes for MMP-7; 77 lymph nodes were positive for CEA or CK20,74 for CEA or MMP-7,71 for CK20 OR MMP-7.One of the 25 limph nodes with 10 benign diseases was positive for CEA and MMP-7. 28 lymph nodes in 11 patients of 20 stageⅠandⅡcases were positive for at least one of the three markers ,implying a staging shift to stageⅢby molecular diagnosis of occult metastasis.Peripheral blood of 23 patients were positive for at least one of the three markers by RT-PCR,13 lymph nodes were positive for CEA,11 for CK20,10 for MMP-7;19 lymph nodes were positive for CEA or CK20,18 for CEA or MMP-7,17 for CK20 or MMP-7.One of the twenty controls was positive for CEA.Conclusion:1 Detection of CEA and CK20 with RT-PCR could enhance the sensitivity of occult metastasis in lymph nodes with coloerectal cancer patients. 2 Detection of CEA,CK20,MMP-7 with RT-PCR could enhance the sensitivity of occult metastasis in periphera blood with colorectal cancer patients.3 Detection of occult metastasis with colorectal cancer may contribute to improve the accuracy of clinical staging,determine patients′prognosis and provide information for adjuvant therapy.